Field of the Disclosure
The present disclosure generally relates to image processing and, more particularly, to an image processing apparatus, an image processing method, and a storage medium.
Description of the Related Art
There has been known a technique for displaying, in real time, a stereoscopic omnidirectional image on a stereoscopic image display device such as a head-mounted display (HMD), for enabling a viewer to view video with high realism. Nevertheless, there has not been established yet a technique for efficiently display a stereoscopic omnidirectional image in real time according to a direction that the viewer faces.
Japanese Patent Laid-Open No. 2012-256274 discloses an image generation method for efficiently displaying a non-stereoscopic omnidirectional image on a planar display. This method is a method of efficiently generating a planar image to be displayed on the display, by dividing in advance an omnidirectional image represented by a coordinate on a spherical surface, into a plurality of planes, and approximating projection conversion from a spherical surface to a plane, to projection conversion from a plane to a plane.
Nevertheless, when an image to be displayed on an HMD is generated, simple projection conversion from a plane to a plane is not sufficient, and in addition to the projection conversion, calculation that considers the distortion of an eyepiece lens is also preferably performed. Thus, the above-described method described in Japanese Patent Laid-Open No. 2012-256274 cannot be directly applied. In other words, the above-described technique described in Japanese Patent Laid-Open No. 2012-256274 cannot reduce calculation cost involved for the processing of generating a stereoscopic display image to be displayed on an HMD, from a stereoscopic omnidirectional image.